He works for the Bush administration...
...and he is trying his desperate best to make his report cast a postive light on an embarrassment for his boss.
THe simple unavoidable truth you keep ignoring is that Mr. Bush said Saddam had hundreds of tons of chemical and biological weapons. He claimed Iraq had a nuclear weapons program. Rumsfeld said "we know he has them, we know where they are."
None of these claims have proven true.
All Mr. Kay has "proven" is that Saddam wanted a weapons program, it doesn't even claim he actually had one. What Mr. Kay's report says says it that its apparent Saddam got rid of his WMDs years before the Bush administration's call to war.